Benchmark: Spacing a number every 3 digits

Tests:

Using map+reverse+join
const str = "1111111"; str.split("").reverse().map((x,i)=>{ if((i + 1) % 3 === 0){ return " "+x; } else { return x; } }).reverse().join("");
Using reduce
const str = "1111111"; str .split("") .reverse() .reduce((acc, cur, i) => { if (i === str.length - 1) return (cur + acc); return (((i + 1) % 3 === 0 ? ' ' : '') + cur + acc); } , "");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using map+reverse+join
Using reduce

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.84 Safari/537.36

Browser/OS: Chrome 68 on Mac OS X 10.13.6

View result in a separate tab

Test name	Executions per second
Using map+reverse+join	1085030.2 Ops/sec
Using reduce	2547176.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

Measuring the performance of JavaScript code is crucial for optimizing applications, and MeasureThat.net provides a great platform for this purpose.

The provided JSON represents two benchmark definitions:

1. **Spacing a number every 3 digits**

This test measures the performance of inserting spaces into a string of repeating numbers (1111111) at regular intervals. The goal is to determine which approach (map+reverse+join, or reduce) is more efficient.

**Options Compared:**

The two approaches being compared are:

a. **Using map+reverse+join**: This method creates an array of characters using the `map()` function, reverses it with `reverse()`, and then joins them back into a string using `join()`. The result is inserted into the original string at regular intervals (every 3 digits).

b. **Using reduce**: This method uses the `reduce()` function to iterate through the array of characters and build the resulting string. It does this by accumulating the previous character and adding it to the current one, with a space added every 3rd iteration.

**Pros and Cons:**

- **map+reverse+join:**
	+ Pros:
		- Can be more readable for developers familiar with these functions.
		- Easy to maintain if the logic is complex.
	+ Cons:
		- Creates an extra array, which can lead to increased memory usage.
		- The `reverse()` function can be expensive in terms of performance.

- **Using reduce:**
	+ Pros:
		- More memory-efficient since it avoids creating an intermediate array.
		- Can be more concise and expressive for developers familiar with the `reduce()` function.
	+ Cons:
		- Might be less readable if not familiar with the `reduce()` function.
		- The logic can become harder to understand due to its functional programming nature.

**Library and Purpose:**

In both test cases, no external libraries are used beyond JavaScript's built-in functions. However, the `map()`, `reverse()`, and `join()` functions are part of the ECMAScript standard and do not require any additional dependencies.

**Special JS Features or Syntax:**

Neither test case uses any special JavaScript features or syntax beyond what's included in the ES6 standard (released in 2015). No modern features like async/await, Promises, or modern array methods are used.

**Other Alternatives:**

In theory, other approaches could be explored to achieve this goal. Some alternatives might include:

* Using a regular expression with the `replace()` function.
* Utilizing string manipulation techniques specific to the JavaScript environment (e.g., using the `String.prototype.replace()` method).
* Employing custom, non-standard methods for spacing numbers.

However, these approaches would likely be less efficient or more difficult to understand than the two methods being compared.

Related benchmarks:

Spacing a number every 3 digits (version: 1)

Comparing performance of: Using map+reverse+join vs Using reduce

Created: 6 years ago by: Registered User

Jump to the latest result

Using map+reverse+join

Using reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):